Cooling system for vehicle

ABSTRACT

An air-conditioning system for a vehicle may include a cooling unit including a radiator, a cooling fan to introduce air in the radiator, a water pump connected to the radiator through the cooling line, and a reserver tank provided on the cooling line to store a cooling fluid, a first condenser connected to the cooling line between the radiator and the reserver tank such that a cooling fluid is introduced and a refrigerant is introduced through a refrigerant line, and the refrigerant is condensed by heat exchange between the cooling fluid and the refrigerant, and a second condenser serially connected to the first condenser on the refrigerant line such that a condensed liquid phase refrigerant is introduced, and disposed on a front of the radiator such that the refrigerant is condensed by an air cooling type through heat exchange between the refrigerant and an outdoor air introduced on driving.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2012-0110929 filed on Oct. 5, 2012, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air-conditioning system for a vehicle that improves overall cooling performance of the air-conditioning system by increasing a condensing rate of refrigerant.

2. Description of Related Art

An air conditioning system includes a compressor to compress a refrigerant, a condenser to condense and liquefy the refrigerant compressed by the compressor, an expansion valve to quickly expand the condensed and liquefied refrigerant by the condenser, and an evaporator to evaporate the refrigerant expanded by the expansion valve.

Because a water cooling type condenser has a heat capacity higher than that of an air cooling type condenser, the water cooling type condenser has a lower condensing pressure, but a temperature difference between a coolant and a refrigerant is small, and a temperature of the coolant is higher than an outdoor air and therefore it is hart to sub cool the refrigerant and overall cooling performance can be deteriorated thereby.

A large capacity of a cooling fan and a radiator are necessary to prevent the above problems, it is disadvantageous in a narrow engine compartment and in an aspect of weight and cost of a vehicle.

And, in an environmentally-friendly vehicle in which electric power parts such as a motor, a stack and the like are applied, after the each of the constituent elements is cooled by a coolant, the coolant is introduced in a condenser. Accordingly, the condensing amount of the refrigerant may be greatly deteriorated along with the increased temperature.

The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing an air-conditioning system for a vehicle having advantages of increasing condensing rate of refrigerant and improving overall cooling performance by using refrigerant and outside air when condensing refrigerant, wherein the refrigerant is condensed by refrigerant to reduce condensing pressure and the refrigerant is condensed by outside air to increase sub cooling effectiveness.

In an aspect of the present invention, an air-conditioning system for a vehicle, may include a cooling unit including a cooling fan to introduce air in a radiator, a reserver tank connected to the radiator through a cooling line to store a cooling fluid, and a water pump to circulate the cooling fluid, a first condenser connected to the cooling line between the radiator and the reserver tank wherein a refrigerant is introduced thereto through a refrigerant line and the refrigerant is condensed by heat exchange between the cooling fluid and the refrigerant, and a second condenser serially connected to the first condenser on the refrigerant line such that a condensed liquid refrigerant is introduced from the first condenser, and the refrigerant is condensed by heat exchange between the refrigerant and an outdoor air introduced on driving by being disposed on a front of the radiator.

An air-conditioning unit including an expansion valve to expand a condensed refrigerant, an evaporator to evaporate an expanded refrigerant by heat exchange with the air, and a compressor to compress the refrigerant of an evaporated gas state, which are connected to each other through the refrigerant line, wherein the compressed refrigerant discharged from the compressor is sequentially passed and condensed in each of the first condenser and the second condenser connected to each other through the refrigerant line.

The first condenser is integrally formed with a receiver drier to separate a remaining gaseous refrigerant in the condensed refrigerant, after the refrigerant connected and introduced through the compressor and the refrigerant line is condensed.

The first condenser is serially connected to the second condenser through the receiver drier.

A heating element is disposed between the water pump and the radiator, in which the cooling fluid that may have been passed the first condenser connected through the cooling line is introduced.

The heating element may include an electric power part, a motor, or a stack in an environmentally-friendly vehicle and a water cooling type intercooler in an internal combustion engine vehicle.

In another aspect of the present invention, an air-conditioning system for a vehicle, which may include an expansion valve to expand a liquid refrigerant, an evaporator to evaporate an expanded refrigerant by heat exchange with air, and a compressor to compress a gaseous refrigerant supplied from the evaporator, which are connected to each other through a refrigerant line, may include a cooling unit including a cooling fan to introduce air in a first radiator, a reserver tank connected to the first radiator through a cooling line to store a cooling fluid, and a water pump connected through the cooling line to circulate the cooling fluid, a first condenser disposed on one side of the first radiator such that the cooling fluid is introduced through the cooling line and the cooling unit, and the refrigerant is condensed by a water cooling type through heat exchange between the cooling fluid and the refrigerant introduced through the cooling line, and a second condenser serially connected to the first condenser on the refrigerant line such that a condensed liquid phase refrigerant is introduced, and disposed on a front of the first radiator such that the refrigerant is condensed by an air cooling type through heat exchange between the refrigerant and an outdoor air introduced on driving.

The first condenser is disposed between the first radiator and the reserver tank.

The first condenser is integrally formed with a receiver drier to separate a remaining gaseous refrigerant in the condensed refrigerant.

The first condenser is connected to the second condenser through the receiver drier.

A heating element is disposed between the first radiator and the water pump through the cooling line.

The heating element may include an electric power part, a motor, or a stack in an environmentally-friendly vehicle and a water cooling type intercooler in an internal combustion engine vehicle.

A second radiator for an internal combustion engine is provided between the first radiator and the cooling fan to cool the internal combustion engine in an internal combustion engine vehicle.

As described above, according to the exemplary embodiments of the present invention, when the refrigerant is primarily condensed through the cooling fluid, the condensing pressure can be reduced since a heat capacity of the cooling fluid is higher than that of the outdoor air, and when the refrigerant is secondarily condensed through the outdoor air, since a temperature difference between the cooling fluid and the refrigerant can be high to be advantageous to the formation of sub cool. Therefore, the overall air-conditioning cooling performance can be improved by increasing the condensing rate of the refrigerant.

In addition, the required works for the compressor can be reduced through the reduced condensing pressure of the refrigerant, and the water temperature of the cooling fluid can be reduced through the increased sub cool. Therefore, the cooling performance can be improved without increasing the capacity of the radiator and the cooling fan.

In addition, if applied to an environmentally-friendly vehicle such as fuel cell and electric vehicles or the like, an electric power part, a motor, a stack or, a heating element such as an intercooler in an internal combustion engine vehicle, and the air-conditioning refrigerant can be cooled by one integrated radiator.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an air-conditioning system for a vehicle according to a various exemplary embodiments of the present invention.

FIG. 2 is a block diagram illustrating an air-conditioning system for a vehicle according to a various exemplary embodiments of the present invention.

FIG. 3 is a block diagram illustrating an air-conditioning system for a vehicle according to a various exemplary embodiments of the present invention.

FIG. 4 is a block diagram illustrating an air-conditioning system for a vehicle according to a various exemplary embodiments of the present invention.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.

In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating an air-conditioning system for a vehicle according to a first exemplary embodiment of the present invention.

Referring to FIG. 1, in the air-conditioning system for a vehicle according to the first exemplary embodiment of the present invention, when condensing a refrigerant, by each using a cooling fluid and an outdoor air, when first condensing a refrigerant through a cooling fluid, a condensing pressure can be reduced, when secondarily condensing the refrigerant through the outdoor air a sub cool can increased and a condensing rate of the refrigerant can be high such that a structure can be achieved in which overall air-conditioning performance can be improved.

To this end, the air-conditioning system 1 for the vehicle is configured to include a cooling unit, a first condenser 10 and a second condenser 20, and the explanations for each of components will be described in more detail as follows.

First, the cooling unit includes a radiator 2 provided on a front of the vehicle, and a cooling fan 4 to introduce air in the radiator 2.

Here, the cooling fan 4 is connected to a controller so that airflows can be adjusted, depending on a condition of the vehicle and a temperature of the refrigerant or the cooling fluid.

In addition, the cooling unit is configured to include a water pump 6 connected through the radiator 2 and the cooling line (hereinafter, referred to as ‘C.L’) by which the cooling fluid flows to circulate the cooling fluid, the cooling line (C.L), and a reserver tank 8 to store the cooling fluid.

In addition, the cooling unit is configured to include the reserver tank 8 connected through the radiator 2 and the cooling line (hereinafter, referred to as ‘C.L’) by which the cooling fluid flows to store the cooling fluid, and the water pump 6 provided on the cooling line (C.L) to circulate the cooling fluid.

Here, the cooling fluid as described above may be configured as a coolant.

In this exemplary embodiment, the first condenser 10 is connected to the cooling line (C.L) between the radiator 2 and the reserver tank 8 to introduce the cooling fluid, and the refrigerant is introduced through a refrigerant line (hereinafter, referred to as ‘R.L’) by which the refrigerant flows in the air-conditioning unit such that the refrigerant is primarily condensed by heat exchange between the cooling fluid and the refrigerant.

Here, the air-conditioning unit is configured to include an expansion valve 22 to expand the condensed refrigerant, an evaporator 24 to evaporate the expanded refrigerant by heat exchange with the air, and a compressor 26 to compress an evaporated gaseous refrigerant, which are connected to each other through the refrigerant line (R.L).

In this exemplary embodiment, the first condenser 10 may be integrally formed with a receiver drier 12 to separate a remaining gaseous refrigerant in the condensed refrigerant, after condensing the refrigerant connected and introduced through the compressor 26 and the refrigerant line (R.L).

The receiver drier 12 can separate a gaseous refrigerant that is not changed into a liquid phase inside a refrigerant of a primarily condensed liquid state such that only a liquid phase refrigerant is discharged in the first condenser 10.

And, the second condenser 20 is serially connected to the first condenser 10 to be introduced with the refrigerant in the liquid phase condensed from the first condenser 10, and disposed on a front of the radiator 2 to secondarily condense the refrigerant through heat exchange between the refrigerant and an outdoor air introduced on driving.

Meanwhile, by the air-conditioning unit, the compressed refrigerant discharged from the compressor 26 is sequentially passed and condensed in the first condenser 10 and the second condenser 20 connected to each other through the refrigerant line (R.L).

Here, the first condenser 10 is serially connected to the second condenser 20 through the receiver drier 12.

Accordingly, the second condenser 20 can be secondarily condensed through the heat exchange between an outdoor air and only the liquid refrigerant that is introduced with the liquid phase in which the gaseous refrigerant that is not changed through the receiver drier 12 of the first condenser 10 is separated.

In other words, in the first exemplary embodiment of the present invention, the first condenser 10 includes a water cooling type in which the coolant introduced by the cooling fluid and the refrigerant introduced into the inside are exchanged, and the second condenser 20 includes an air cooling type in which the refrigerant and outdoor air introduced from the outside during the driving of the vehicle.

Therefore, the first condenser 10 consisted of the water cooling type can cool the refrigerant using a coolant that has a high heat transfer coefficient compared to the outdoor air to reduce a condensing pressure in the inside.

In addition, the second condenser 20 consisted of the air cooling type can cool only gaseous refrigerant that the refrigerant condensed while passing through the first condenser 10 is supplied through receiver drier 12 using the outdoor air, such that a temperature difference between the outdoor air and the refrigerant can be high to be advantageous to the formation of sub cool and the total heat of the cooling line (R.L) can be reduced.

That is, the air-conditioning system 1 according to the first exemplary embodiment of the present invention can be applied to both of the first and second condensers 10 and 20 each applied with the water cooling type and the air cooling type. Accordingly, since the condensing pressure reduction that is an advantage of the water cooling type and a favorable position to obtain the sub cooling formation that is an advantage of the air cooling type can be effectively used, and drawbacks according to each types can be compensated, the overall cooling air-conditioning performance can be improved.

Therefore, according to the first exemplary embodiment of the present invention, if the air-conditioning system 1 having the structure as described above is applied, the cooling fluid and the outdoor air are each used when condensing the refrigerant. Accordingly, when the refrigerant is primarily condensed through the cooling fluid, the condensing pressure can be reduced since a heat capacity of the cooling fluid is higher than that of the outdoor air, and when the refrigerant is secondarily condensed through the outdoor air, since a temperature difference between the cooling fluid and the refrigerant can be high to be advantageous to the formation of sub cool. Therefore, the overall air-conditioning cooling performance can be improved by increasing the condensing rate of the refrigerant.

In addition, the required works for the compressor can be reduced through the reduced condensing pressure of the refrigerant, thereby reducing operating fuel consumption, and reducing the total amount of heat of the cooling line (C.L) can be reduced through the increased sub cool, thereby reducing the water temperature of the cooling fluid that is circulated along with the cooling line (R.L). Therefore, since the cooling performance can be improved without increasing the capacity of the radiator 2 and the cooling fan 4, space utilization can be increased by simplifying a layout in a narrow engine room, and weight reduction and the manufacturing cost can be saved.

FIG. 2 is a block diagram illustrating an air-conditioning system for a vehicle according to a second exemplary embodiment of the present invention.

Referring to FIG. 2, the air-conditioning system 100 according to the second exemplary embodiment of the present invention may be applied to a fuel cell vehicle, an electric vehicle and the like, which are environmentally-friendly vehicles, wherein the cooling fluid and the outdoor air are each used when condensing the refrigerant. Accordingly, when the refrigerant is primarily condensed through the cooling fluid, the condensing pressure can be reduced, and when the refrigerant is secondarily condensed through the outdoor air, the sub cool can be increased. Therefore, the overall air-conditioning cooling performance can be improved by increasing the condensing rate of the refrigerant.

According to the second exemplary embodiment of the present invention, the air-conditioning system 100 may be configured to include a cooling unit, a first condenser 110 and a second condenser 120.

First, the cooling unit may be configured to include a radiator 102 provided on a front of the vehicle, a cooling fan 104 to introduce air in the radiator 102, a reserver tank 108 connected through the radiator 2 and the cooling line (hereinafter, referred to as ‘C.L’) by which the cooling fluid flows to store the cooling fluid, and the water pump 106 provided on the cooling line (C.L) to circulate the cooling fluid.

Here, the cooling fan 104 is connected to a controller so that airflows can be adjusted, depending on a condition of the vehicle and a temperature of the refrigerant or the cooling fluid, and the cooling fluid may be configured as a coolant.

In the second exemplary embodiment of the present invention, the first condenser 110 is connected to the cooling line (C.L) between the radiator 102 and the reserver tank 108 to introduce the cooling fluid, and the refrigerant is introduced through a refrigerant line (hereinafter, referred to as ‘R.L’) by which the refrigerant flows in the air-conditioning unit such that the refrigerant is primarily condensed by heat exchange between the cooling fluid and the refrigerant.

Here, the air-conditioning unit is configured to include an expansion valve 122 to expand the condensed refrigerant, an evaporator 124 to evaporate the expanded refrigerant by heat exchange with the air, and a compressor 126 to compress an evaporated gaseous refrigerant, which are connected to each other through the refrigerant line (R.L).

In this exemplary embodiment, the first condenser 110 may be integrally formed with a receiver drier 112 to separate a remaining gaseous refrigerant in the condensed refrigerant, after condensing the refrigerant connected and introduced through the compressor 126 and the refrigerant line (R.L).

The receiver drier 112 can separate a gaseous refrigerant that is not changed into a liquid phase inside a refrigerant of a primarily condensed liquid state such that only a liquid phase refrigerant is discharged in the first condenser 110.

In addition, the second condenser 120 is serially connected to the first condenser 110 to be introduced with the refrigerant in the liquid phase condensed from the first condenser 110, and disposed on a front of the radiator 102 to secondarily condense the refrigerant through heat exchange between the refrigerant and an outdoor air introduced on driving.

Here, a heating element 130 may be disposed between the water pump 108 and the radiator 102 in which the cooling fluid stored in the reserver tank 108 is introduced after the cooling fluid is connected through the cooling line (C.L) and passed through the first condenser 110.

The heating element 130 may be configured to include an electric power part, motor or stack applied to an environmentally-friendly vehicle such as a fuel cell vehicle, an electric vehicle and the like, and the water cooling type intercooler in an internal combustion engine vehicle.

That is, the heat of the heating element 130 can be cooled by the coolant discharged from the first condenser 110 through the cooling line (C.L).

Accordingly, after the heating element 130 is cooled by the coolant, the coolant is circulated along the cooling line (C.L) and re-introduced into the radiator 102 to be cooled through the water pump 106 while maintaining the heating state. In addition, after the coolant is stored in reserver tank 108 by the water pump 106 and then introduced into the first condenser 110 to be heat-exchanged. The operation is repeatedly performed.

On the other hand, in the air-conditioning unit, the compressed refrigerant discharged from the compressor 126 may be condensed while being sequentially passed through the first condenser 110 and the second condenser 120 connected to each other through the refrigerant line (R.L).

Here, the first condenser 110 may be serially connected to the second condenser 120 through the receiver drier 12.

Accordingly, the second condenser 120 can be secondarily condensed through the heat exchange between an outdoor air and only the liquid refrigerant that is introduced with the liquid phase at which the gaseous refrigerant that is not changed through the receiver drier 112 of the first condenser 110 is separated.

At this time, the receiver drier 112 can also perform a function of filtering a foreign material contained in the refrigerant.

That is, in the second exemplary embodiment of the present invention, the first condenser 110 includes a water cooling type in which the coolant introduced by the cooling fluid and the refrigerant introduced into the inside are exchanged, and the second condenser 120 includes an air cooling type in which the refrigerant and outdoor air introduced from the outside during the driving of the vehicle.

Therefore, the first condenser 110 consisted of the water cooling type can cool the refrigerant using a coolant that has a high heat transfer coefficient compared to the outdoor air to reduce a condensing pressure in the inside.

In addition, the second condenser 120 consisted of the air cooling type can cool only gaseous refrigerant that the refrigerant condensed while passing through the first condenser 110 is supplied through receiver drier 112 using the outdoor air, such that a temperature difference between the outdoor air and the refrigerant can be high to be advantageous to the formation of sub cool and the total heat of the cooling line (R.L) can be reduced.

Therefore, according to the second exemplary embodiment of the present invention, if the air-conditioning system 100 having the structure as described above is applied, the cooling fluid and the outdoor air are each used when condensing the refrigerant. Accordingly, when the refrigerant is primarily condensed through the cooling fluid, the condensing pressure can be reduced since a heat capacity of the cooling fluid is higher than that of the outdoor air, and when the refrigerant is secondarily condensed through the outdoor air, since a temperature difference between the cooling fluid and the refrigerant can be high to be advantageous to the formation of sub cool. Therefore, the overall air-conditioning cooling performance can be improved by increasing the condensing rate of the refrigerant.

In addition, the required works for the compressor can be reduced through the reduced condensing pressure of the refrigerant, thereby reducing operating fuel consumption, and reducing the total amount of heat of the cooling line (C.L) can be reduced through the increased sub cool, thereby reducing the water temperature of the cooling fluid that is circulated along with the cooling line (R.L). Therefore, since the cooling performance can be improved without increasing the capacity of the radiator 102 and the cooling fan 104, space utilization can be increased by simplifying a layout in a narrow engine room, and weight reduction and the manufacturing cost can be saved.

In addition, if applied to an environmentally-friendly vehicle, such as fuel cell and electric vehicles or the like, an electric power part, a stack, and the heating element 130 such as an intercooler in an internal combustion engine vehicle, and a refrigerant can be cooled by one integrated radiator 102. Accordingly, the cooling performance can be improved and the configuration can be simplified.

FIG. 3 is a block diagram illustrating an air-conditioning system for a vehicle according to a third exemplary embodiment of the present invention.

Referring to FIG. 3, the air-conditioning system 200 according to the third exemplary embodiment of the present invention may be applied to a fuel cell vehicle, an electric vehicle and the like, which are environmentally-friendly vehicles, wherein the cooling fluid and the outdoor air are each used when condensing the refrigerant. Accordingly, when the refrigerant is primarily condensed through the cooling fluid, the condensing pressure can be reduced, and when the refrigerant is secondarily condensed through the outdoor air, the sub cool can be increased. Therefore, the overall air-conditioning cooling performance can be improved by increasing the condensing rate of the refrigerant.

According to the third exemplary embodiment of the present invention, the air-conditioning system 200 may be configured to include an expansion valve 202 to expand the liquid refrigerant, an evaporator 204 to evaporate the expanded refrigerant by the expansion valve 202 by heat exchange with the air, and a compressor 206 to compress a gaseous refrigerant supplied from the evaporator 204, which are basically connected to each other through the refrigerant line (R.L).

Here, according to the third exemplary embodiment of the present invention, the air-conditioning system 200 may be configured to further include a cooling unit, a first condenser 216 and a second condenser 220.

First, the cooling unit may be configured to include a radiator 208 provided on a front of a vehicle, a cooling fan 210 to introduce air in the radiator 208, a reserver tank 214 connected through the radiator 208 and the cooling line (C.L) by which the cooling fluid flows to store the cooling fluid, and a water pump 212 connected through the cooling line (C.L) to circulate the cooling fluid.

The cooling fan 204 in the cooling unit as configured above is connected to a controller so that airflows can be adjusted, depending on a condition of the vehicle and a temperature of the refrigerant or the cooling fluid, and the cooling fluid may be configured as a coolant.

Here, a heating element 230 connected through the cooling line (C.L) may be disposed between the radiator 208 and the water pump 230.

The heating element 230 may be configured to include an electric power part, a motor or stack applied to an environmentally-friendly vehicle such as a fuel cell vehicle, an electric vehicle and the like, or a stack, and a water cooling type intercooler in an internal combustion engine vehicle.

That is, after the coolant is passed to the first condenser 216 from the radiator 208 by the operation of the water pump 212, the generated heat of the heating element 230 is cooled while the coolant stored in reserver tank 214 is introduced through the cooling line (C.L).

Accordingly, after the heating element 230 is cooled by the coolant, the coolant is circulated along the cooling line (C.L) and re-introduced into the radiator 202 to be cooled through the water pump 206 while maintaining the heating state. In addition, after the coolant is introduced into the first condenser 210 to be heat-exchanged with the refrigerant. The operation is repeatedly performed.

Meanwhile, by means of the first condenser 216, the cooling fluid, which is a coolant, is connected and introduced through the cooling line (C.L.) and the cooling unit, and the refrigerant is condensed by a water cooling type through heat exchange between the cooling fluid and the refrigerant introduced through the refrigerant line.

Here, the first condenser 216 may be disposed on one side of the radiator 208 between the reserver tank 214 and the radiator 208.

In addition, the first condenser 216 may be integrally formed with a receiver drier 218 that separates a remaining gaseous refrigerant in the condensed refrigerant, after condensing the refrigerant connected and introduced through the compressor 206 and the refrigerant line (R.L).

The receiver drier 218 can separate a gaseous refrigerant that is not changed into a liquid phase inside a refrigerant of a primarily condensed liquid state such that only a liquid phase refrigerant is discharged in the first condenser 216, and perform a function of removing a foreign material contained in the refrigerant at the same time.

In addition, the second condenser 220 is serially connected to the first condenser 216 on the refrigerant line (R.L) such that the condensed liquid phase refrigerant can be introduced, and disposed on the front of the radiator 208 such that the refrigerant can be condensed by the air cooling type through heat exchange between the refrigerant and an outdoor air introduced on driving.

Here, the first condenser 216 and the second condenser 220 may be serially connected to each other. At this time, the first condenser 216 may be connected to the second condenser 220 through the receiver drier 218.

In other words, in the third exemplary embodiment of the present invention, the first condenser 216 includes a water cooling type in which the coolant introduced by the cooling fluid and the refrigerant introduced into the inside are exchanged, and the second condenser 220 includes an air cooling type in which the refrigerant and outdoor air introduced from the outside during the driving of the vehicle.

Therefore, the first condenser 216 consisted of the water cooling type can cool the refrigerant using a coolant that has a high heat transfer coefficient compared to the outdoor air to reduce a condensing pressure in the inside.

In addition, the second condenser 220 consisted of the air cooling type can cool only gaseous refrigerant that the refrigerant condensed while passing through the first condenser 216 is supplied through receiver drier 218 using the outdoor air, such that a temperature difference between the outdoor air and the refrigerant can be high to be advantageous to the formation of sub cool and the total amount of heat of the cooling line (R.L) can be reduced.

In addition, since the coolant to be circulated along the cooling line (C.L) in the cooling unit can cool the heat generated from the heating element 230 using the radiator 208, the overall configuration can be simplified.

Therefore, according to the third exemplary embodiment of the present invention, if the air-conditioning system 200 having the structure as described above is applied, the cooling fluid and the outdoor air are each used when condensing the refrigerant. Accordingly, when the refrigerant is primarily condensed through the cooling fluid, the condensing pressure can be reduced since a heat capacity of the cooling fluid is higher than that of the outdoor air, and when the refrigerant is secondarily condensed through the outdoor air, since a temperature difference between the cooling fluid and the refrigerant can be high to be advantageous to the formation of sub cool. Therefore, the overall air-conditioning cooling performance can be improved by increasing the condensing rate of the refrigerant.

In addition, the required works for the compressor can be reduced through the reduced condensing pressure of the refrigerant, thereby reducing operating fuel consumption, and reducing the total amount of heat of the cooling line (C.L) can be reduced through the increased sub cool, thereby reducing the water temperature of the cooling fluid that is circulated along with the cooling line (R.L). Therefore, since the cooling performance can be improved without increasing the capacity of the radiator 208 and the cooling fan 210, space utilization can be increased by simplifying a layout in a narrow engine room, and weight reduction and the manufacturing cost can be saved.

In addition, if applied to an environmentally-friendly vehicle such as fuel cell and electric vehicles or the like, an electric power part, a stack or, the heating element 230 such as an intercooler in an internal combustion engine vehicle, and a refrigerant can be cooled by one integrated radiator 208. Accordingly, the cooling performance can be improved and the configuration can be simplified.

FIG. 4 is a block diagram illustrating an air-conditioning system for a vehicle according to a fourth exemplary embodiment of the present invention.

Referring to FIG. 4, the air-conditioning system 300 for a vehicle according to the fourth exemplary embodiment of the present invention can be applied to a vehicle to which an internal combustion engine is provided, wherein in a case a refrigerant is condensed each using a cooling fluid and an outdoor air, the condensing pressure can be reduced, when the refrigerant is primarily condensed through the cooling fluid, and a sub cool can be increased, when the refrigerant is secondarily condensed through the outdoor air, such that overall air-conditioning cooling performance can be improved.

According to the fourth exemplary embodiment of the present invention, the air-conditioning system 300 may be configured to include an expansion valve 303 to expand the liquid refrigerant, an evaporator 304 to evaporate the expanded refrigerant by the expansion valve 303 by heat exchange with the air, and a compressor 306 to compress a gaseous refrigerant supplied from the evaporator 304, which are basically connected to each other through the refrigerant line (R.L).

Here, according to the fourth exemplary embodiment of the present invention, the air-conditioning system 300 may be configured to further include a cooling unit, a first condenser 316 and a second condenser 320.

First, the cooling unit may be configured to include a radiator 308 provided on a front of a vehicle, a cooling fan 310 to introduce air in the radiator 308, a reserver tank 314 connected through the radiator 308 and the cooling line (C.L) by which the cooling fluid flows to store the cooling fluid, and a water pump 312 connected through the cooling line (C.L) to circulate the cooling fluid.

The cooling fan 304 in the cooling unit as configured above is connected to a controller so that airflows can be adjusted, depending on a condition of the vehicle and a temperature of the refrigerant or the cooling fluid, and the cooling fluid may be configured as a coolant.

Here, a radiator 330 for an internal combustion engine may be further included between the radiator 308 and the cooling fan 310 in an internal combustion engine vehicle.

The radiator 330 for the internal combustion engine is connected to the internal combustion engine of the vehicle through a separate cooling line that is different from the cooling line (C.L) consisting the cooling unit, such that after heat generated from the internal combustion engine is cooled, the heated cooling fluid can be cooled through the outdoor air and operation of the cooling fan 310, and the cooling fluid can be again supplied.

Meanwhile, by means of the first condenser 316, the cooling fluid, which is a coolant, is connected and introduced through the cooling line (C.L.) and the cooling unit, and the refrigerant is condensed by a water cooling type through heat exchange between the cooling fluid and the refrigerant introduced through the refrigerant line (R.L).

Here, the first condenser 316 may be disposed on one side of the radiator 308 between the reserver tank 314 and the radiator 308.

In addition, the first condenser 316 may be integrally formed with a receiver drier 318 that separates a remaining gaseous refrigerant in the condensed refrigerant, after condensing the refrigerant connected and introduced through the compressor 306 and the refrigerant line (R.L).

The receiver drier 318 can separate a gaseous refrigerant that is not changed into a liquid phase inside a refrigerant of a primarily condensed liquid state such that only a liquid phase refrigerant is discharged in the first condenser 316, and perform a function of removing a foreign material contained in the refrigerant at the same time.

In addition, the second condenser 320 is serially connected to the first condenser 316 on the refrigerant line (R.L) such that the condensed liquid phase refrigerant can be introduced, and disposed on the front of the radiator 308 such that the refrigerant can be condensed by the air cooling type through heat exchange between the refrigerant and an outdoor air introduced on driving.

Here, the first condenser 316 and the second condenser 320 may be serially connected to each other. At this time, the first condenser 316 may be connected to the second condenser 320 through the receiver drier 318.

In other words, in the fourth exemplary embodiment of the present invention, the first condenser 316 includes a water cooling type in which the coolant introduced by the cooling fluid and the refrigerant introduced into the inside are exchanged, and the second condenser 320 includes an air cooling type in which the refrigerant and outdoor air introduced from the outside during the driving of the vehicle.

Therefore, the first condenser 316 consisted of the water cooling type can cool the refrigerant using a coolant that has a high heat transfer coefficient compared to the outdoor air to reduce a condensing pressure in the inside.

In addition, the second condenser 320 consisted of the air cooling type can cool only gaseous refrigerant that the refrigerant condensed while passing through the first condenser 316 is supplied through receiver drier 318 using the outdoor air, such that a temperature difference between the outdoor air and the refrigerant can be high to be advantageous to the formation of sub cool and the total amount of heat of the cooling line (R.L) can be reduced.

Therefore, according to the fourth exemplary embodiment of the present invention, if the air-conditioning system 300 having the structure as described above is applied, the cooling fluid and the outdoor air are each used when condensing the refrigerant. Accordingly, when the refrigerant is primarily condensed through the cooling fluid, the condensing pressure can be reduced since a heat capacity of the cooling fluid is higher than that of the outdoor air, and when the refrigerant is secondarily condensed through the outdoor air, since a temperature difference between the cooling fluid and the refrigerant can be high to be advantageous to the formation of sub cool. Therefore, the overall air-conditioning cooling performance can be improved by increasing the condensing rate of the refrigerant.

In addition, the required works for the compressor can be reduced through the reduced condensing pressure of the refrigerant, thereby reducing operating fuel consumption, and reducing the total amount of heat of the cooling line (C.L) can be reduced through the increased sub cool, thereby reducing the water temperature of the cooling fluid that is circulated along with the cooling line (R.L). Therefore, since the cooling performance can be improved without increasing the capacity of the radiator 308 and the cooling fan 310, space utilization can be increased by simplifying a layout in a narrow engine room, and weight reduction and the manufacturing cost can be saved.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

What is claimed is:
 1. An air-conditioning system for a vehicle, comprising: a cooling unit including a cooling fan to introduce air in a radiator, a reserver tank connected to the radiator through a cooling line to store a cooling fluid, and a water pump to circulate the cooling fluid; a first condenser connected to the cooling line between the radiator and the reserver tank wherein a refrigerant is introduced thereto through a refrigerant line and the refrigerant is condensed by heat exchange between the cooling fluid and the refrigerant; and a second condenser serially connected to the first condenser on the refrigerant line such that a condensed liquid refrigerant is introduced from the first condenser, and the refrigerant is condensed by heat exchange between the refrigerant and an outdoor air introduced on driving by being disposed on a front of the radiator.
 2. The air-conditioning system of claim 1, wherein an air-conditioning unit including an expansion valve to expand a condensed refrigerant, an evaporator to evaporate an expanded refrigerant by heat exchange with the air, and a compressor to compress the refrigerant of an evaporated gas state, which are connected to each other through the refrigerant line, and wherein the compressed refrigerant discharged from the compressor is sequentially passed and condensed in each of the first condenser and the second condenser connected to each other through the refrigerant line.
 3. The air-conditioning system of claim 1, wherein the first condenser is integrally formed with a receiver drier to separate a remaining gaseous refrigerant in the condensed refrigerant, after the refrigerant connected and introduced through the compressor and the refrigerant line is condensed.
 4. The air-conditioning system of claim 3, wherein the first condenser is serially connected to the second condenser through the receiver drier.
 5. The air-conditioning system of claim 1, wherein a heating element is disposed between the water pump and the radiator, in which the cooling fluid that has been passed the first condenser connected through the cooling line is introduced.
 6. The air-conditioning system of claim 5, wherein the heating element includes an electric power part, a motor, or a stack in an environmentally-friendly vehicle and a water cooling type intercooler in an internal combustion engine vehicle.
 7. An air-conditioning system for a vehicle, which includes an expansion valve to expand a liquid refrigerant, an evaporator to evaporate an expanded refrigerant by heat exchange with air, and a compressor to compress a gaseous refrigerant supplied from the evaporator, which are connected to each other through a refrigerant line, comprising: a cooling unit including a cooling fan to introduce air in a first radiator, a reserver tank connected to the first radiator through a cooling line to store a cooling fluid, and a water pump connected through the cooling line to circulate the cooling fluid; a first condenser disposed on one side of the first radiator such that the cooling fluid is introduced through the cooling line and the cooling unit, and the refrigerant is condensed by a water cooling type through heat exchange between the cooling fluid and the refrigerant introduced through the cooling line; and a second condenser serially connected to the first condenser on the refrigerant line such that a condensed liquid phase refrigerant is introduced, and disposed on a front of the first radiator such that the refrigerant is condensed by an air cooling type through heat exchange between the refrigerant and an outdoor air introduced on driving.
 8. The air-conditioning system of claim 7, wherein the first condenser is disposed between the first radiator and the reserver tank.
 9. The air-conditioning system of claim 7, wherein the first condenser is integrally formed with a receiver drier to separate a remaining gaseous refrigerant in the condensed refrigerant.
 10. The air-conditioning system of claim 9, wherein the first condenser is connected to the second condenser through the receiver drier.
 11. The air-conditioning system of claim 7, wherein a heating element is disposed between the first radiator and the water pump through the cooling line.
 12. The air-conditioning system of claim 11, wherein the heating element includes an electric power part, a motor, or a stack in an environmentally-friendly vehicle and a water cooling type intercooler in an internal combustion engine vehicle.
 13. The air-conditioning system of claim 7, wherein a second radiator for an internal combustion engine is provided between the first radiator and the cooling fan to cool the internal combustion engine in an internal combustion engine vehicle. 